Sumita Optical Glass Inc.

Sumita Optical Glass Inc. developed its K-PG325 Super Vidron optical glass to replace the less durable plastic now used in optical molded parts. This material can be precision-molded at approximately 325 °C, making it suitable for use with a wide range of die materials, including nickel, iron and stainless steel. The company, based in Saitama City, Japan, says that the glass can be molded into minute, complex shapes at low cost, and that it is more durable than plastic, allowing it to be used in severe environmental conditions.

The glass has no lead or arsenic and can be used to manufacture products typically composed of plastic, such as fly-eye lenses, microlens arrays, Fresnel lenses and large aspheric lenses. Because of its low fluorescence, which is as weak as that of fused silica, it also can be used as an alternative to fused silica for biomedical applications.

A noncrystalline, inorganic mixture of various metallic oxides fused by heating with glassifiers such as silica, or boric or phosphoric oxides. Common window or bottle glass is a mixture of soda, lime and sand, melted and cast, rolled or blown to shape. Most glasses are transparent in the visible spectrum and up to about 2.5 µm in the infrared, but some are opaque such as natural obsidian; these are, nevertheless, useful as mirror blanks. Traces of some elements such as cobalt, copper and...